JP6431679B2 - Artificial teeth - Google Patents

Description

  The present invention relates to an artificial tooth. More specifically, the present invention relates to an artificial tooth having an opal effect.

The materials used for artificial teeth have no biofouling and biocompatibility. In addition to physical properties such as surface hardness, wear resistance, bending strength, and bending modulus, color tone, gloss, and translucency It is necessary to satisfy such aesthetics. Furthermore, in recent years, as the patient's demand for aesthetics increases, an artificial tooth having an opal effect more similar to that of a natural tooth (that is, bluish by reflected light and orange by transmitted light) is desired.
In the patent document 1, the present applicant has proposed a dental composition for use in expressing an opal effect in an artificial tooth or the like.
The dental composition described in Patent Document 1 contains fine titanium dioxide particles having an average particle diameter of 0.01 to 0.10 μm as a resin matrix monomer, an organic filler, and an inorganic filler.
As shown in FIG. 6, an artificial tooth using this dental composition as an enamel layer in a multi-layer artificial tooth 44 having a dentin layer 42 laminated on a core layer 41 and an enamel layer 43 laminated thereon. (That is, the lip side and the tongue side are coated with the same composition.), The opal effect is exhibited, but the change in the color tone due to the opal effect of the cut edge 44a is caused by reflected light. It can be said that the color change due to the opal effect is similar to that of natural teeth, but the color change due to transmitted light is poor and monotonous, and the color tone due to the opal effect due to reflected light and transmitted light changes slightly. It cannot be said to be close to a tooth.

JP 2008-23003 A

  The present invention has been made as a result of intensive studies in view of the above situation, and an object thereof is to provide an artificial tooth exhibiting an opal effect that approximates a natural tooth at a cut edge or the like.

In order to solve the above problems, an artificial tooth according to the present invention has (1) an enamel layer in which a lip side enamel layer and a lingual enamel layer are joined at a cut edge, and the lip side enamel layer and the The lingual enamel layer is an artificial tooth made of a composition having a different composition and having a different color tone expressed by an opal effect in transmitted light. The lip side enamel layer is composed of 22 parts by weight of methyl methacrylate and ethylene as a resin matrix monomer. Composition containing 2 parts by weight of glycol dimethacrylate, 38 parts by weight of polymethyl methacrylate having an average molecular weight of 500,000 as an organic filler and an average particle diameter of 20 μm, and 0.01 part by weight of titanium dioxide having an average particle diameter of 0.25 μm as an inorganic filler. The resin matrix monomer of the product is formed by polymerization and curing, and the lingual enamel layer has a resin matrix. 22 parts by weight of methyl methacrylate and 2 parts by weight of ethylene glycol dimethacrylate as an organic monomer, 38 parts by weight of polymethyl methacrylate having an average molecular weight of 500,000 and an average particle diameter of 20 μm as an organic filler, and dioxide having an average particle diameter of 0.25 μm as an inorganic filler The resin matrix monomer of the composition containing 0.02 part by weight of titanium is obtained by polymerization and curing.
(2) In the above (1), the layer thickness of the labial enamel layer and the lingual enamel layer in the cut edge may be different.
Here, “layer thickness” refers to the thickness of the layer before and after the artificial tooth (in the direction from the lip side surface to the lingual side surface).
(3) In the above (1) or (2), an organic-inorganic composite filler may be further contained.

Since the present invention is configured as described above, the following effects can be obtained.
That is, the color tone expressed by the opal effect of the transmitted light at the cut edge or the like is rich in change, and an artificial tooth approximated to a natural tooth can be obtained.
More specifically, for example, when the artificial tooth of the present invention is applied to the oral cavity, when the mouth is wide open with a smile, the incisal edge of the artificial tooth is caused by light incident from the buccal side, that is, near the mouth corner. The part or the like exhibits an opal effect with transmitted light, and an orange-reddish color exhibits a kind of fine fluctuation such as a mottled shape having a different density depending on the place, giving an impression more similar to natural teeth.
This is because the lip side enamel layer and the lingual enamel layer are joined at the incision, etc., so that the opal effect of the buccal enamel layer and the opal effect of the lingual enamel layer at the incision are intertwined Therefore, although it is thought that the color tone due to the opal effect at the edge of the artificial tooth is similar to that of natural teeth, it is not clear.
And by changing the layer thickness of the lip side enamel layer and the lingual side enamel layer at the cut edge, the color change due to the opal effect in the transmitted light can take into account the effect of the layer thickness, Therefore, the color tone change by the transmitted light can be arbitrarily set by designing various layer thicknesses.

1 shows an anterior maxillary tooth as one embodiment of an artificial tooth according to the present invention, wherein (a) is a front view (lip side view), (b) is a cross-sectional view taken along line AA, and (c) is a bottom view (cut edge side view). ), (D) are cross-sectional views along the line BB. It is explanatory drawing of the manufacturing method of the artificial tooth shown in FIG. It is sectional drawing of the maxillary front tooth as other embodiment of the artificial tooth of this invention. It is sectional drawing of the maxillary front tooth as further another embodiment of the artificial tooth of this invention. It is sectional drawing of the maxillary front tooth as further another embodiment of the artificial tooth of this invention. It is an artificial tooth which used the dental composition of patent document 1 for the enamel layer.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be shown and the present invention will be described in more detail. Of course, the present invention is not limited to the following embodiments.
FIG. 1 shows an anterior maxillary tooth as an embodiment of the artificial tooth of the present invention, (a) is a front view (labial side view), (b) is a cross-sectional view taken along the line AA, and (c) is a bottom view ( (Cut edge side view), (d) is a cross section taken along line BB.
An artificial tooth 1 shown in FIG. 1 is a resin-based artificial tooth molded by a mold, and is a multilayer upper front tooth composed of three layers of a core layer 2, a dentin layer 3, and an enamel layer 4. The lip side enamel layer 4a and the lingual side enamel layer 4b are joined and integrated at least at the cut edge 1a.
More specifically, the joint at the cut edge 1a of the lip side enamel layer 4a and the lingual enamel layer 4b reaches the cut edge from the tip of the dentin layer 3 in the longitudinal direction, and in the near-centrifugal direction in the width direction. However, the present invention is not limited to this. The joint surface here is shown as a flat surface, but is not limited to this, and may include a complex curved surface including irregularities.
The thickness (layer thickness) from the joint surface 4c at the cut edge portion 1a of the labial enamel layer 4a and the lingual enamel layer 4b is shown in the left-right direction in FIG. However, the thickness of each part in the longitudinal direction and the near-centrifugal direction is not uniform and may vary in various ways because the surface shape of the cutting edge 1a of the artificial tooth 1 may be complicated. become.
Although not shown, in the case of the artificial tooth 1 molded by a molding die, the parting line by the molding die usually indicates the boundary between the labial enamel layer 4a and the lingual enamel layer 4b.

In the enamel layer, the resin matrix monomer in a paste-like or bowl-like composition containing a resin matrix monomer, an organic filler, and an inorganic filler having an average particle size of 0.11 to 0.25 μm described below is polymerized and cured. However, the present invention is not limited to this.
The lip-side enamel layer 4a and the lingual-side enamel layer 4b have different compositions, and thus have different colors of opal effects.
Here, “the composition is different” means that at least one of the types of materials constituting the composition, the composition ratio, the average particle diameter of the inorganic filler, and the like are different.
In order to make the color tone expressed by the opal effect caused by transmitted light different, the type of inorganic filler, its average particle size, and composition ratio play a large role.
The opal effect at the cutting edge of the artificial tooth and the like is rich in color tone change with reflected light, and also rich in color tone change with transmitted light, and an artificial tooth approximated to natural teeth can be obtained.
As described above, the thickness from the joint surface 4c of the cut edge 1a of the lip side enamel layer 4a and the lingual enamel layer 4b is not uniform and varies in various ways. The change in color tone due to the opal effect is also affected by the thickness of the layer, and from this point, it is possible to obtain an artificial tooth that approximates a natural tooth.

Hereinafter, the composition for the enamel layer used for the lip side enamel layer and the lingual side enamel layer will be described.
The resin matrix monomer used in the composition for the enamel layer may be (meth) acrylate having one unsaturated double bond or (meth) acrylate having two or more unsaturated double bonds. That's fine.

  Examples of (meth) acrylate having one unsaturated double bond include methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, hydroxypropyl methacrylate, tetrahydro Examples include furfuryl methacrylate, glycidyl methacrylate, 2-methoxyethyl methacrylate, 2-ethylhexyl methacrylate, and benzyl methacrylate.

  Examples of the (meth) acrylate having two or more unsaturated double bonds include 2-hydroxy-1,3-dimethacryloxypropane, 2,2-bis (methacryloxyphenyl) propane, and 2,2-bis [4 -(2-hydroxy-3-methacryloxypropoxy) phenyl] propane, 2,2-bis (4-methacryloxydiethoxyphenyl) propane, 2,2-bis (4-methacryloxypolyethoxyphenyl) propane, ethylene glycol Dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol Methacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, pentaerythritol trimethacrylate, trimethylolmethane trimethacrylate, pentaerythritol tetramethacrylate, di-2-methacryloxyethyl-2,2,4-trimethylhexamethylene dicarbamate and These acrylates and methacrylates and acrylates having a urethane bond in the molecule can be exemplified.

  The resin matrix monomer may be one kind of (meth) acrylate having one unsaturated double bond, or two or more kinds may be used in combination. Further, (meth) acrylate having one unsaturated double bond and (meth) acrylate having two or more unsaturated double bonds may be used in combination. In this case, a combination of one (meth) acrylate having one unsaturated double bond and one (meth) acrylate having two or more unsaturated double bonds, two or more one unsaturated A combination of a (meth) acrylate having a double bond and one (meth) acrylate having two or more unsaturated double bonds, and a (meth) acrylate having two or more one unsaturated double bonds; A combination of two or more (meth) acrylates having two or more unsaturated double bonds can be employed.

It is preferable to add a polymerization initiator to the resin matrix monomer in advance.
As the polymerization initiator, a heat polymerization initiator, a chemical polymerization initiator, or a photopolymerization initiator can be used.

  As the heat polymerization type initiator, organic peroxides, azo compounds and the like are mainly used. As the organic peroxide, aromatic diacyl peroxides and peroxyesters which are regarded as esters of perbenzoic acid are preferable. Benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-tolyl Peroxide, t-butylperoxybenzoate, di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-di {( o-benzoyl) benzoylperoxy} hexane. As the azo compound, azobisisobutyronitrile and the like, and other organometallic compounds such as tributyl boron can be used.

  Examples of the chemical polymerization type initiator include a combination of an organic peroxide and a tertiary amine. As the organic peroxide, aromatic diacyl peroxides and peroxyesters which are regarded as esters of perbenzoic acid are preferable. Benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-tolyl Peroxide, t-butylperoxybenzoate, di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-di {( o-benzoyl) benzoylperoxy} hexane. As the tertiary amine, a tertiary amine in which an aromatic group is directly substituted with a nitrogen atom is preferable, and N, N-dimethyl-p-toluidine, N, N-dimethylaniline, N-methyl-N-β-hydroxy is preferred. Aniline, N, N-di (β-hydroxyethyl) -aniline, N, N-di (β-hydroxyethyl) -p-toluidine, N, N-di (β-hydroxypropyl) -aniline, N, N- Examples include di (β-hydroxypropyl) -p-toluidine, ethyl N, N-dimethylaminobenzoate, and isoamyl N, N-dimethylaminobenzoate.

As the photopolymerization initiator, a combination of a sensitizer and a reducing agent is generally used.
Sensitizers include camphorquinone, benzyl, diacetyl, benzyldimethyl ketal, benzyl diethyl ketal, benzyl di (2-methoxyethyl) ketal, 4,4'-dimethylbenzyl-dimethyl ketal, anthraquinone, 1-chloroanthraquinone, 2- Chloroanthraquinone, 1,2-benzanthraquinone, 1-hydroxyanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, 1-bromoanthraquinone, thioxanthone, 2-isopropylthioxanthone, 2-nitrothioxanthone, 2-methylthioxanthone, 2,4 -Dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chloro-7-trifluoromethylthioxanthone, thioxanthate -10,10-dioxide, thioxanthone-10-oxide, benzoin methyl ether, benzoin ethyl ether, isopropyl ether, benzoin isobutyl ether, benzophenone, bis (4-dimethylaminophenyl) ketone, 4,4'-bisdiethylaminobenzophenone, acyl A phosphine oxide derivative, a compound containing an azide group, and the like can be exemplified, and these are used alone or in combination.

As the reducing agent, a tertiary amine is generally used. Tertiary amines include N, N-dimethyl-p-toluidine, N, N-dimethylaminoethyl methacrylate, triethanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, 4-dimethylamino. An example is isoamyl benzoate. Other reducing agents include benzoyl peroxide, sodium sulfinate derivatives, organometallic compounds, and the like.
The polymerization reaction can be achieved by irradiating the photopolymerization initiator with actinic rays such as ultraviolet rays or visible rays. As the light source, various high-pressure, high-pressure, medium-pressure and low-pressure mercury lamps, chemical lamps, carbon arc lamps, metal halide lamps, fluorescent lamps, tungsten lamps, xenon lamps, argon ion lasers and the like are used.

  In addition, a polymerization inhibitor, an oxidation stabilizer, a discoloration inhibitor, a plasticizer, a surfactant, an antibacterial agent, an ultraviolet absorber, a pigment, and a dye can be added to the resin matrix monomer as necessary.

  Examples of organic fillers include methyl methacrylate, ethyl methacrylate, 2-ethylhexyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, alkyl methacrylate, methoxyethyl methacrylate, 2-hydroxybutyl methacrylate, benzyl methacrylate, and phenyl methacrylate. , Phenoxyethyl methacrylate, hydroxyethyl methacrylate, homopolymers of these acrylates, copolymers thereof, or mixtures of these homopolymers and copolymers. These organic fillers can be obtained by suspension polymerization (pearl polymerization). In general, it is preferable to use a granular or powdery organic filler having an average particle size of 100 μm or less. If the average particle size is 100 μm or less, the resin matrix monomer in the artificial tooth of the present invention is polymerized and cured with good aesthetics. If it exceeds 100 μm, the organic filler becomes pearly on the surface of the polymerized and cured product. Appearing, the aesthetics are impaired and the cured body becomes brittle.

  The organic filler is preferably 20 to 180 parts by weight with respect to 100 parts by weight of the resin matrix monomer. The organic filler swells with the resin matrix monomer and contributes to making the composition into a bowl or paste. If the organic filler is less than 20 parts by weight, a cocoon-like or paste-like composition cannot be obtained, workability is inferior, and molding becomes difficult, which is not preferable. Further, when the organic filler exceeds 180 parts by weight, the powder component is excessive, and is unfavorable because it becomes bulky, the moldability and workability deteriorate, and the abrasion resistance of the resin matrix monomer that has been polymerized and cured is inferior. Absent.

Examples of inorganic fillers having an average particle size of 0.11 to 0.25 μm include various glasses such as barium glass, alumina glass, potassium glass, titanium dioxide, silica, synthetic zeolite, calcium phosphate, feldspar, aluminum silicate, calcium silicate One or more selected from the group consisting of magnesium carbonate, quartz, nonporous atomized colloidal silica, nonporous colloidal alumina, and nonporous wet colloidal silica can be employed.
When the average particle size is less than 0.11 μm, the inorganic filler has a strong aggregating action, and it becomes difficult to develop the opal effect because it is not uniformly dispersed in the resin matrix monomer. If the average particle diameter exceeds 0.25 μm, it is not preferable because the opal effect can hardly be exhibited because it becomes larger than the wavelength of light.

  The inorganic filler in the enamel layer is preferably 0.01 to 20 parts by weight with respect to 100 parts by weight of the resin matrix monomer. If the inorganic filler is less than 0.01 parts by weight, it is not preferable because a resin matrix monomer is polymerized and cured, but it is difficult to express a sufficient color tone in the expression of the opal effect by transmitted light. On the other hand, when the inorganic filler exceeds 20 parts by weight, the resin matrix monomer is polymerized and cured, and the translucency is inferior. A more preferable range is 0.02 to 0.09 parts by weight.

  As the inorganic filler, it is preferable to use one that has been surface-treated with a coupling agent in advance. As the coupling agent, an organofunctional silane coupling agent, a titanate coupling agent, or a zircoaluminate coupling agent can be used.

  Organofunctional silane coupling agents include γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltri Methoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane and the like can be employed.

  Titanate coupling agents include isopropyl triisostearoyl titanate, isopropyl tridodecyl benzene sulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopyrubis (dioctyl phosphate) titanate, tetraoctyl bis (ditridecyl phosphate) Titanate, tetra (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltriocanoyl titanate, isopropyl Dimethacrylisostearoyl titanate, isopropylisostearoyl diacryl titanate DOO, isopropyl tri (dioctyl phosphate) titanate, may be employed isopropyl tricumylphenyl titanate, isopropyl tri (N- diaminoethyl) titanate, dicumyl phenyloxy acetate titanate, and diisostearoyl ethylene titanate or the like.

  As the dialcoaluminate coupling agent, alcohol cabcomodo, glycol cabcomodo and the like can be employed.

The amount of these coupling agents added is preferably 0.1 to 25 parts by weight with respect to 100 parts by weight of the inorganic filler. When the addition amount of the coupling agent is less than 0.1 parts by weight, there is no effect as a coupling agent, the adhesion between the inorganic filler and the resin matrix monomer is insufficient, and the physical properties of the artificial teeth are obtained. The properties are inferior and are not preferred. Moreover, when the addition amount of a coupling agent exceeds 25 weight part, an excess coupling agent will function as a plasticizer or a defect, and when it is set as an enamel layer, its physical property etc. are inferior, and is not preferable.
In order to treat the inorganic filler with a coupling agent, the inorganic filler and the coupling agent may be appropriately mixed.

  The composition for the enamel layer may contain an organic-inorganic composite filler as necessary. Various organic and inorganic composite fillers such as barium glass, alumina glass and potassium glass, silica, synthetic zeolite, calcium phosphate, feldspar, aluminum silicate, calcium silicate, magnesium carbonate, quartz, nonporous atomized colloid From one or more inorganic powders selected from the group of silica, non-porous colloidal alumina, non-porous wet-type colloidal silica, etc., and the resin matrix monomer described as being used in the present invention Examples thereof include a mixture of at least one selected monomer, polymerization, and pulverization. Since the surface of the organic-inorganic composite filler is a resin, there is an advantage that the affinity and wettability with the resin matrix monomer are good and uniform mixing is possible.

As the inorganic powder used for the organic-inorganic composite filler, those having an average particle size of 20 μm or less are usually used, but fine particles having an average particle size of 50 nm or less can be used as small particles. When the average particle size exceeds 20 μm, the resin matrix monomer of the composition for the enamel layer is polymerized and hardened, and the contact feeling with the mucosal surface is deteriorated. Of course, the inorganic filler described above may be used as the inorganic powder. A combination in which the average particle size of the inorganic powder used in the organic-inorganic composite filler is relatively larger than the average particle size of the inorganic filler is a hybrid type composite, so that fine adjustment of mechanical properties is facilitated.
As the inorganic powder used for the organic-inorganic composite filler, it is preferable to use a powder that has been surface-treated with a coupling agent in advance. As the coupling agent, the aforementioned organofunctional silane coupling agent, titanate coupling agent, and zircoaluminate coupling agent can be used. The coupling treatment of the inorganic powder used for the organic-inorganic composite filler may be appropriately mixed with the inorganic powder and the coupling agent in the same manner as the coupling treatment of the inorganic filler.

  More specifically, the production of the organic-inorganic composite filler is more specifically performed by the inorganic powder, the monomer, the heating polymerization initiator, for example, a peroxide such as benzoyl peroxide, or an azo compound such as azobisisobutyronitrile. Further, if necessary, the above-mentioned coupling agent, coloring agent, oxidation stabilizer, ultraviolet absorber, pigment and the like are added as appropriate, mixed with stirring, polymerized at 80 to 120 ° C., and average particle diameter of 1 with a ball mill or the like. What was obtained by grinding to about 50 μm can be employed. When the average particle size is less than 1 μm, the specific surface area becomes large, and when the composition for the enamel layer is used, it takes a long time to uniformly mix with other components, and it tends to become hard and workability is poor. It is not preferable. When the average particle diameter exceeds 50 μm, for example, when artificial teeth are used, the feeling of contact with the mucosal surface is deteriorated, which is not preferable.

  In the enamel layer of the artificial tooth of the present invention, an organic-inorganic composite filler is further used for the resin matrix monomer, the organic filler, and the inorganic filler having an average particle size of 0.11 to 0.25 μm. In this case, the organic-inorganic composite filler is preferably 5 to 100 parts by weight with respect to 100 parts by weight of the resin matrix monomer. When the organic / inorganic composite filler is less than 5 parts by weight, a polymer-cured resin matrix monomer of the enamel layer composition tends to be brittle. On the other hand, when the organic / inorganic composite filler exceeds 100 parts by weight, the moldability and workability are deteriorated, which is not preferable, and the resin matrix monomer which has been polymerized and cured is inferior in wear resistance.

The artificial tooth 1 shown in FIG. 1 has a lip-side enamel layer 4a and a lingual-side enamel layer 4b joined to a resin-based molded body 5 in which a dentin layer 3 is laminated on a core layer 2 at least at a cut edge 1a. Thus, it can manufacture by carrying out lamination | stacking formation.
Examples of the core layer 2 and the dentin layer 3 include (meth) acrylate resins used for artificial teeth. As the (meth) acrylate resin, a dental resin, a hard resin, and a composite resin can be used, and a dental resin is preferable.
As the molded body 5, those molded appropriately using these resins can be used, but are not limited thereto.

In order to mold the multilayer artificial tooth 1 shown in FIG. 1 in which the lip-side enamel layer 4a and the lingual-side enamel layer 4b are joined to the molded body 5 at least at the cutting edge 1a using a molding die, for example, What is necessary is just to follow the manufacturing method of the artificial tooth described in 298599 gazette.
Select and weigh the composition for the lip-side enamel layer from the resin matrix monomer, organic filler, and inorganic filler with an average particle size of 0.11 to 0.25 μm, and add a polymerization initiator, pigment, etc. as necessary. The mixture is mixed uniformly and allowed to elapse for a predetermined time to prepare a cocoon-shaped resin (a composition for the lip side enamel layer) for the lip side enamel layer. Similarly, the composition for the lingual enamel layer is selected and weighed from the resin matrix monomer, the organic filler, and the inorganic filler having an average particle size of 0.11 to 0.25 μm, and a polymerization initiator and a pigment as necessary. Etc. are added and mixed to be uniform, and after a predetermined time, a candy-like resin for the lingual enamel layer (a composition for the lingual enamel layer) is prepared.
As described above, the composition of the bowl-shaped resin for the labial enamel layer is different from that of the bowl-shaped resin for the lingual enamel layer.
Next, as shown in FIG. 2 (a), in the state in which the molded body 5 is formed of the base part mold 7, the labial dentin mold 8a, and the lingual dentin mold 8b, the labial dentin mold 8a is replaced with the labial enamel mold. In place of 9a, as shown in FIG. 2 (b), in the cavity 10a formed by the base mold 7, the molded body 5, the lip enamel mold 9a, and the lingual dentin mold 8b, the lip enamel layer 4a is used. The cage-shaped resin adjusted to the above is filled, and polymerization and curing are performed in a state where the mold is pressed. Then, the tongue-side dentin mold 8b is replaced with the tongue-side enamel mold 9b, and as shown in FIG. 2 (c), the base part mold 7, the molded body 5 on which the lip-side enamel layer 4a is formed, the lip-side enamel mold 9a. In the cavity 10b formed by the lingual enamel mold 9b, the ridge-shaped resin adjusted for the lingual enamel layer 4b is filled and polymerized and cured in a state where the mold is pressurized, whereby the artificial tooth 1 is formed. Molding is performed (FIG. 2D).
In addition, description about the removal of the burr | flash formed in the middle of shaping | molding etc. is abbreviate | omitted.
Although it can be said that the molded body 5 is clear from the above description, the molded body 5 may be manufactured according to the method for manufacturing artificial teeth described in JP-A-2004-298599, but is not limited thereto.

You may make it build a lip side enamel layer and a lingual side enamel layer in a molded object irrespective of a shaping | molding die.
In this case, a paste-like resin adjusted for the lip side enamel layer and a paste resin adjusted for the lingual enamel layer may be used. As the polymerization initiator, a photopolymerization initiator, chemical polymerization start may be used. Although an agent is preferable, a heat polymerization initiator may be used.
When a photopolymerization initiator is used, after the lip-side enamel layer and the lingual-side enamel layer are built up on the molded body with a brush or the like, light for polymerization may be irradiated.

FIG. 3 is a cross-sectional view of an anterior maxillary tooth as another embodiment of the artificial tooth of the present invention.
The artificial tooth 11 shown in FIG. 3 uses a molded body 13 in which the dentin layer 12 reaches the base side of the lingual side, and the lip side enamel layer 14 a and the lingual enamel layer 14 b are laminated on the molded body 13. The lingual side of the dentin layer 12 is exposed. 14c shows a joint surface.
Since others are the same as the artificial tooth shown in FIG. 1, detailed description is abbreviate | omitted.

FIG. 4 is a cross-sectional view of an anterior maxillary tooth as still another embodiment of the artificial tooth according to the present invention.
The artificial tooth 21 shown in FIG. 4 uses a molded body 25 in which a dentin layer 23 is laminated with the lingual side of the core layer 22 exposed, and the lip-side enamel layer 24a and the lingual-side enamel layer 24b are formed into the molded body 25. The lingual side of the core layer 22 is exposed. Reference numeral 24c denotes a joint surface.
Since others are the same as the artificial tooth shown in FIG. 1, detailed description is abbreviate | omitted.

FIG. 5 is a sectional view of an anterior maxillary tooth as still another embodiment of the artificial tooth according to the present invention.
The artificial tooth 31 shown in FIG. 5 uses a molded body 33 in which the dentin layer 32 reaches the basal side of the tongue, and the lip side enamel layer 34 a and the lingual enamel layer 34 b are laminated on the molded body 33. Has been. Reference numeral 34c denotes a joint surface.
Since others are the same as the artificial tooth shown in FIG. 1, detailed description is abbreviate | omitted.

  The artificial tooth of the present invention is not limited to the core layer, the dentin layer, and the enamel layer. The artificial tooth may be a multilayer of more than that, or a dentin layer and an enamel layer. The lip side enamel layer and the lingual enamel layer are joined at least at the cut edge, and the entire artificial tooth is molded with the composition for the lip side enamel layer and the composition for the lingual enamel layer. Also good.

  The artificial tooth of the present invention is not limited to the above-described maxillary anterior teeth, but mainly targets the anterior teeth.

Next, an example is shown with a comparative example, and it explains in more detail. Of course, the present invention is not limited to the following examples.
(Example 1)
Resin matrix monomer, methyl methacrylate (MMA), ethylene glycol dimethacrylate (EDMA), organic filler, polymethyl methacrylate (PMMA), polymerization catalyst, benzoyl peroxide (BPO), inorganic filler, titanium dioxide The parts by weight shown in Example 1 of Table 1 were weighed and mixed so as to be uniform, and after a predetermined time, a resin for the lip-like enamel layer and a resin for the lingual enamel layer were obtained.
Here, as the PMMA, a powder having an average molecular weight of 500,000 and an average particle diameter of 20 μm was used.
Titanium dioxide having an average particle size of 0.25 μm was used.
The average particle diameter of PMMA and the average particle diameter of titanium dioxide were measured by a laser particle size distribution analyzer SALD-2000A manufactured by Shimadzu Corporation.
The titanium dioxide is obtained by silane coupling treatment with γ-methacryloxypropyltrimethoxysilane. In the silane coupling treatment, 1 part by weight of a coupling agent was used with respect to 100 parts by weight of titanium dioxide.

The obtained resin for the lip-side enamel layer and the resin for the lingual enamel layer were each placed in a mold ring (φ20 mm × 2 mm) and polymerized by heating at 80 ° C. and 300 MPa for 10 minutes. Various types of samples (both having a thickness of 2 mm) were obtained.
Two types of the obtained samples were surface-polished with # 1000 water-resistant abrasive paper, both sides were mirror-finished by buffing, and a test sample for lip side enamel layer (φ20mm × 1.0mm) and tongue A test sample (φ20 mm × 0.5 mm) for the side enamel layer is prepared, and these test samples are overlapped to form a test specimen having a thickness of 1.5 mm. The background of the test specimen is white for evaluation of the opal effect. The colorimetric value when the color was changed and the colorimetric value when the background was black were measured by the following test method, and the color difference Δa * b * with respect to the a * b * value indicating the color tone excluding lightness was calculated.
The results are as shown in Example 1 in Table 1.

<Colorimetric test method>
A colorimetric value obtained when a spectroscopic color difference meter (SE-2000, manufactured by Nippon Denshoku Industries Co., Ltd.) is used in a constant temperature and humidity chamber with a temperature of 23 ° C. and a humidity of 50%, and the background is white with respect to the test specimen. And the colorimetric value when the background was black was measured.

(Example 2)
The same MMA, EDMA, PMMA, BPO, and titanium dioxide as used in Example 1 were weighed and mixed so as to be uniform as shown in Example 2 of Table 1, and the mixture was stirred for a predetermined period of time to form a bowl. A resin for the lip side enamel layer and a resin for the lingual side enamel layer were obtained.
The obtained resin for the lip side enamel layer and the resin for the lingual enamel layer were placed in the mold ring in the same manner as in Example 1, and heat-polymerized under the same conditions as in Example 1 to produce two types. Samples were obtained.
Using the obtained two types of samples, in the same manner as in Example 1, a test sample for the lip side enamel layer (φ20 mm × 0.5 mm) and a test sample for the lingual enamel layer (φ20 mm × 1.0 mm) ), These test samples were superposed on a test body having a thickness of 1.5 mm, colorimetric values were measured by the colorimetric test method, and a color difference Δa * b * was calculated.
The results are as shown in Example 2 in Table 1.

(Comparative Example 1)
The same MMA, EDMA, PMMA, BPO, and titanium dioxide used in Example 1 were weighed and mixed so as to be uniform as shown in Comparative Example 1 in Table 2 and allowed to elapse for a predetermined period of time. The resin for the enamel layer was obtained.
The obtained resin for the bowl-shaped enamel layer was filled in the mold ring (φ20 mm × 2 mm) and subjected to heat polymerization under the same conditions as in Example 1 to obtain a sample.
Using the obtained sample, a test body for enamel layer (φ20 mm × 1.5 mm) was prepared in the same manner as in Example 1, and the colorimetric value was measured by the colorimetric test method, and the color difference Δa * b *. Was calculated.
The results are as shown in Comparative Example 1 in Table 2.

(Comparative Example 2)
The same MMA, EDMA, PMMA, BPO and titanium dioxide used in Example 1 were weighed and mixed so as to be uniform as shown in Comparative Example 2 in Table 2 and allowed to elapse for a predetermined time to form a bowl. The resin for the enamel layer was obtained.
The obtained resin for the bowl-shaped enamel layer was filled in the mold ring (φ20 mm × 2 mm) and subjected to heat polymerization under the same conditions as in Example 1 to obtain a sample.
Using the obtained sample, a test body for enamel layer (φ20 mm × 1.5 mm) was prepared in the same manner as in Example 1, and the colorimetric value was measured by the colorimetric test method, and the color difference Δa * b *. Was calculated.
The results are as shown in Comparative Example 2 in Table 2.

In the composition as in Examples 1 and 2, the inorganic filler, for example, titanium dioxide having an average particle diameter of 0.25 μm, is 0.02 to 0.09 parts by weight with respect to 100 parts by weight of the resin matrix monomer. It has been confirmed that it is better.
In addition, the change in opal color tone due to the thickness is that when a plurality of specimens having the same composition and different thicknesses are prepared and observed with transmitted light, there is a peak in Δa * b *, which is thinner than that? Alternatively, the result that Δa * b * tends to decrease when the layer is thick is obtained with the specimen of the composition of the lip-side enamel layer and the specimen of the composition of the lingual enamel layer of Example 1.
From the above description of the present specification and drawings, it can be said that the following technical idea is disclosed in the present specification.
(A) The lip-side enamel layer and the lingual-side enamel layer have an enamel layer joined at a cut edge, and the lip-side enamel layer and the lingual-side enamel layer are composed of compositions having different compositions, and transmit An artificial tooth having a different color tone expressed by an opal effect with light, wherein the lip side enamel layer and the lingual side enamel layer are 20 to 180 parts by weight of an organic filler with respect to 100 parts by weight of a resin matrix monomer, and an average An artificial tooth, wherein the resin matrix monomer of a composition containing 0.01 to 20 parts by weight of an inorganic filler having a particle size of 0.11 to 0.25 µm is polymerized and cured.
(B) The artificial tooth according to (a), wherein the lip-side enamel layer and the lingual-side enamel layer are different in thickness at the cut edge.
Here, “layer thickness” refers to the thickness of the layer before and after the artificial tooth (in the direction from the lip side surface to the lingual side surface).
(C) The inorganic filler is barium glass, alumina glass, potassium glass, titanium dioxide, silica, synthetic zeolite, calcium phosphate, feldspar, aluminum silicate, calcium silicate, magnesium carbonate, quartz, nonporous atomized method The artificial tooth according to (a) or (b), which is one or more selected from the group consisting of colloidal silica, nonporous colloidal alumina, and nonporous wet colloidal silica.
(D) The artificial tooth according to (c), wherein the inorganic filler is titanium dioxide.
(E) The artificial tooth according to (a), (b), (c) or (d), further comprising an organic-inorganic composite filler.

DESCRIPTION OF SYMBOLS 1 Artificial tooth 1a Cutting edge 2 Core layer 3 Dentin layer 4a Lip side enamel layer 4b Tongue side enamel layer 4c Joining surface 5 Molded body

Claims (3)

The lip-side enamel layer and the lingual-side enamel layer have an enamel layer joined at a cut edge, and the lip-side enamel layer and the lingual-side enamel layer are composed of compositions having different compositions, and transmit light in the transmitted light. An artificial tooth with a different color tone expressed by the opal effect,
The lip side enamel layer comprises 22 parts by weight of methyl methacrylate and 2 parts by weight of ethylene glycol dimethacrylate as a resin matrix monomer, 38 parts by weight of polymethyl methacrylate having an average molecular weight of 500,000 and an average particle size of 20 μm as an organic filler, and an inorganic filler. The resin matrix monomer of the composition containing 0.01 part by weight of titanium dioxide having an average particle size of 0.25 μm is polymerized and cured, and the lingual enamel layer is 22 parts by weight of methyl methacrylate as the resin matrix monomer. 2 parts by weight of ethylene glycol dimethacrylate, 38 parts by weight of polymethyl methacrylate having an average molecular weight of 500,000 as an organic filler and an average particle diameter of 20 μm, and 0.02 part by weight of titanium dioxide having an average particle diameter of 0.25 μm as an inorganic filler Include Artificial teeth, wherein the resin matrix monomer Narubutsu are those formed by polymerizing and curing.   The artificial tooth according to claim 1, wherein the lip side enamel layer and the lingual enamel layer in the cut edge have different layer thicknesses.   The artificial tooth according to claim 1, further comprising an organic-inorganic composite filler.

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